The present disclosure relates to a rotational shaft, and more particularly, to a flexible drive shaft.
Drive shafts are known to experience multiple misalignments that may include angular misalignment, parallel offset, axial displacement, and any combination of the three. Flexing of the drive shaft is unavoidable because the loads applied during normal operation, the alignment process, and the installation process may cause the shaft to bend. Yet further, thermal expansion, worn bearings, and installation errors may further contribute toward misalignment.
Traditional, flexible, drive shafts may utilize a sliding spline either at the end or the middle of the drive shaft to accommodate larger axial displacements. Additionally, disks in the couplings may accommodate small axial displacements. Unfortunately, this may contribute toward increases in weight and cost. The sliding spline may need periodic replacement, and the drive shafts may also need an axial limiting device inside of the couplings to prevent damage. Further improvements in the flexible drive shaft's capability is desirable to reduce weight, cost, and maintenance.